Example: Reverse a Number using While Loop in Java

// Reverse a Number using While Loop
import java.util.Scanner;

// Main class containing the entry point of the program
public class Main {
    public static void main(String[] args) {
        // Step 1: Initialize a Scanner to read input from the user
        Scanner scanner = new Scanner(System.in);

        // Step 2: Prompt the user to enter a number
        System.out.print("Enter a number to reverse: ");
        int originalNumber = scanner.nextInt();

        // Step 3: Initialize a variable to store the reversed number
        int reversedNumber = 0;
        int tempNumber = originalNumber; // Use a temporary variable to avoid modifying originalNumber

        // Step 4: Use a while loop to extract digits and build the reversed number
        while (tempNumber != 0) {
            int digit = tempNumber % 10; // Get the last digit
            reversedNumber = reversedNumber * 10 + digit; // Append the digit to reversedNumber
            tempNumber /= 10; // Remove the last digit from tempNumber
        }

        // Step 5: Print the original and reversed numbers
        System.out.println("Original Number: " + originalNumber);
        System.out.println("Reversed Number: " + reversedNumber);

        // Step 6: Close the scanner
        scanner.close();
    }
}